The present invention relates to a turbocharger assembly, and in particular a turbocharger assembly comprising voltage boost electronics.
Turbochargers are well known devices for supplying air to the intake of an internal combustion engine at pressures above atmospheric (boost) pressure. A conventional turbocharger typically comprises an exhaust gas driven turbine wheel mounted on a rotatable shaft within a turbine housing. Rotation of the turbine wheel rotates a compressor wheel mounted on the other end of the shaft within a compressor housing. The compressor wheel delivers compressed air to the intake manifold of the engine, thereby increasing engine power.
A turbocharger assembly may comprise a turbocharger and other apparatus, for example, actuators for controlling a flow of fluid in, around, or associated with the operation of the turbocharger (or an engine system which the turbocharger assembly forms a part of). A turbocharger assembly might additionally or alternatively comprise one or more conduits that form part of, or (at least in use) are in connection with the turbocharger. The aforementioned actuators may be arranged to control a flow of fluid through those one or more conduits.
Electronics may be used in the control of one or more parts of a turbocharger assembly, for example in the control of one or more actuators of that assembly. In automotive electrical systems, a voltage applied by a typical battery may vary widely, for example from 9V to 17V for a nominally 12V battery, or for example from 18V to 34V for a nominally 24V battery. In addition, voltage supplied by the battery may suffer from transient surges in excess of the aforementioned values, for example during load dump, jump start, and/or inductive switching events.
Transient suppression circuits are typically used for preventing or limiting the transient surges mentioned above from damaging control electronics of electric actuators. Such transient suppression electronics typically are not designed to regulate a steady value of the voltage level, and instead accept the performance variation that results from the variation in supplied voltage. A few designs do attempt to regulate the supplied voltage level, and such regulation is downwards. For example, this means than an electric actuator (e.g. a motor or the like) optimised for use in connection with a 12V battery can be used in conjunction with a 24V battery system without suffering from performance variation. In other words, the voltage supplied by the 24V battery would be regulated down by the actuator control electronics (i.e. the down regulation components thereof) to a voltage suitable for use with the electric actuator (e.g. 12V).
The approach of regulating the voltage downwards has at least one associated disadvantage. A disadvantage is that if the voltage supplied to the down regulator drops below a target level (e.g. below 12V for the example provided in the previous paragraph), the regulator will be unable to maintain a constant output voltage at a desired level, and the output voltage will instead follow the input voltage downwards. This may result in degradation in performance of the actuator. In extreme situations, this may result in the actuator not functioning as intended, or in the actuator not functioning at all. A low voltage applied to the actuator may alternatively or additionally limit the available power or torque density (e.g. for example if the actuator is a motor or the like), and this may result in the actuator not being able to perform a certain function.
It is an object of the present Invention to provide a turbocharger assembly which at least partially obviates or mitigates a disadvantage of the prior art, whether identified herein or elsewhere, or which provides an alternative to an existing or proposed turbocharger assembly.